What Is Your Gut Telling You?
Microbiome and Disease
Microbiome studies are still too new to reveal whether certain bacteria might cause disease or whether disease might breed certain bacteria -- or whether the relationship is something else altogether. For now, scientists are only making links between a person’s bacterial makeup and the presence of certain diseases. Regardless of whether a cause-and-effect relationship is found, looking at gut bacteria could become a way for doctors to diagnose certain diseases earlier and more accurately, Petrosino says.
Research has shown links to colon cancer, Crohn’s disease, ulcerative colitis, diabetes, and obesity. While these conditions might seem more related to the intestines or metabolism, gut bacteria has been linked to diseases throughout the body.
Certain bacteria can strengthen the immune system, while others can promote the inflammation that’s part of autoimmune diseases like rheumatoid arthritis, recent research shows.
“Many diseases -- of the skin, lungs, joints, and other tissue -- are caused by inflammation,” Petrosino says. “A bacterial imbalance can lead to elevated inflammation that can advance disease.”
A recent study shows that people with untreated rheumatoid arthritis, an inflammatory autoimmune disease, have more of a particular inflammatory bacteria in their intestines and less of a known beneficial bacteria than their healthy counterparts.
Researchers have also uncovered connections between intestinal bacteria and anxiety, depression, obsessive-compulsive disorder, ADD, autism, and Alzheimer’s disease, among others. Some chalk up this link to intestinal bacteria’s ability to make small molecules (called metabolites) that can reach the brain and impact how it works.
Care and Feeding of Your Microbiome
As the roster of diseases linked to intestinal microbes continues to grow, the burning question is this: Can you change your gut bacteria and cure or get rid of your risk for a particular disease?
“If you make a long-term dietary change -- for example from a high-fat, high-sugar diet to a leaner, more high-fiber diet -- it’s possible that you could reshape your microbiome, giving it a healthier profile,” Petrosino says. This could improve immune function, lower inflammation, and lead to overall better health. Not just a healthy diet, he says, but a more varied diet may be key to fostering a diverse and healthy microbiome. Exercise might diversify gut bacteria, too, says a recent study that showed athletes had more varied intestinal microbes than their non-athlete peers.
Understanding the microbiome won’t just highlight the importance of diet and exercise. It could lead to advances in medical treatments, too. For example, doctors now do fecal transplants on people with difficult-to-treat c. difficilebacterial infections. The doctor puts a solution of healthy feces into the sick person’s colon through their rectum. The feces have healthy gut bacteria that can fight the infection. Ongoing research is looking at using this procedure in other conditions.